May/June 2018

Frailty Syndrome: Identify and Implement an Exercise Regimen
By Margaret Danilovich, PhD, PT, DPT, GCS
Today's Geriatric Medicine
Vol. 11 No. 3 P. 12

It's important to identify frailty and develop a resistance exercise program to improve muscle strength and mass, which are reduced in aging and further decreased by frailty.

A thin, weak, inactive, kyphotic older adult with multiple chronic conditions presents to the emergency department after a fall. It may be tempting to describe this individual as frail; however, frailty is not an adjective, but rather a syndrome affecting approximately 20% of all older adults.1 Lacking a standardized definition, frailty has been proposed as a medical syndrome marked by a constellation of biomedical factors that reduce an individual's capacity to withstand and recover from stressors. Functional deficits such as balance impairments, weakness, decreased endurance, and reduced walking speed contribute to difficulties completing activities of daily living (ADLs) and further restrict physical activity capabilities. This accelerates frailty, limits health and participation in ADLs, and reduces independence.

Frailty Assessment
One of the most widely used definitions of frailty is the Fried phenotype, which classifies individuals as frail in the presence of three of the five following criteria: exhaustion, involuntary weight loss, low physical activity, slow gait speed, and poor muscle strength. Prefrail individuals have one or two criteria.2 In a systematic review of frailty assessment tools by de Vries et al, 75% of intervention studies used the categorical scoring system (eg, frail, prefrail, and nonfrail) to evaluate intervention success.3 The major strengths of using a categorical approach to measuring frailty are that it is the most commonly used approach in the literature, making comparisons to other studies easier; allows for risk stratification according to different profiles (ie, frail, prefrail, and nonfrail); and defines the presence or absence of a condition (ie, exhaustion, involuntary weight loss, sedentary behavior, slow gait speed, and poor muscle strength), allowing for interventions to target specific criteria contributing to frailty.

Despite these benefits, a potential weakness to the categorical approach is that a beneficial intervention that reduces frailty within a given category might have an insufficient magnitude to overcome the thresholds required to change frailty category. Using the categorical scoring system would not be specific enough to detect changes within frailty category. To address this limitation, the continuous scoring system (frailty index or accumulation of deficits model) may better capture the dynamic nature of frailty.4 The frailty index is composed of a checklist of clinical conditions or diseases and the number of variables can be modified from 20 to 92 conditions. A frailty index score is calculated by dividing the number of clinical conditions or diseases by the total number assessed, with scores closer to 1 representing greater frailty. The major benefit of this approach is greater sensitivity to change, making this tool potentially more useful to evaluate intervention effectiveness and evaluate health status over time. Furthermore, this scale is not subject to arbitrary cut-points for frailty categories.

An emerging frailty assessment tool designed for primary care settings is the SHARE-FI (Survey of Health, Ageing and Retirement in Europe-Frailty Index).5 A free calculator is available online for both men and women and has been translated into Italian, Spanish, French, Polish, and German. The SHARE-FI assesses fatigue, appetite, weakness, walking difficulties, and low physical activity, which are constructs from Fried's frailty phenotype criteria. A composite frailty score is generated based on these items, and that score is used to classify individuals as nonfrail, prefrail, or frail.

Assessments from the SHARE-FI include the following:
1. In the last month, have you had too little energy to do the things you wanted to do? (Yes or No)

2. What has your appetite been like? (diminution in desire for food and/or eating less than usual, no change in desire for food and/or eating the same as usual, or increase in desire for food and/or eating more than usual)

3. Two repetitions of grip strength measured via handheld dynamometry on each hand

4. Because of a health or physical problem, do you have any difficulty doing any of the following everyday activities, excluding any difficulties you expect to last less than three months? Walking 100 meters (Yes or No), Climbing one flight of stairs without resting (Yes or No)

5. How often do you engage in activities that require a low or moderate level of energy such as gardening, cleaning the car, or taking a walk? (More than once per week, once per week, one to three times per month, or hardly ever/never)

The FRAIL scale is a five-item frailty screening tool that simply requires asking five brief questions.6 Individuals answering positively to three or more questions are screened as frail. Positive responses to one to two questions identify an individual as prefrail.

1. Are you fatigued?
2. Can you climb one flight of stairs?
3. Can you walk one block?
4. Do you have greater than five illnesses?
5. Do you have weight loss greater than 5% of body weight?

One of the primary challenges of identifying frailty is that there is no international standard measurement for frailty. In a systematic review of frailty measurement, 29 different frailty measures were identified with administration times ranging from less than five minutes to 30 minutes.3 Furthermore, some measures evaluate frailty in domains beyond the physical, addressing cognitive, social, and psychological frailty. Frailty assessment tools vary from self-reported measures to objective assessments that involve grip strength measurement or calculating energy expenditure through the Minnesota Leisure Time Physical Activity Questionnaire. These more time- and resource-intensive assessment tools are a barrier for routine clinical implementation, yet self-report measures may be subject to recall bias or less appropriate for individuals with cognitive impairment. Despite the challenges with frailty measurement, a recent frailty consensus conference offered that all people over the age of 70 should be screened yearly for physical frailty.1

Evidence for Resistance and Aerobic Interventions
Frailty intervention trials have tested pharmacotherapy, nutrition, exercise, and comprehensive medical programs, with exercise trials being the most consistently effective intervention. Resistance exercise is the primary mechanism for improving muscle strength and mass that are reduced in aging and further decreased by frailty. While intervention effectiveness may not be as robust in frail older adults compared with healthy older adults and younger populations, those with frailty can nevertheless improve muscle quality in response to training. Research shows that progressive resistance exercise increases muscle mass by 2% to 9%, improves strength by 17% to 43%, and increases gait speed in frail older adults.7

Despite the known effectiveness of resistance exercise in improving function, only 10% of older adults engage in this mode of exercise at the recommended dose of two times per week.8 In comparison, walking is the most consistently preferred mode of exercise among older adults, and the participation rate is double that of resistance exercise.9 As an intervention, walking addresses the frailty criteria of gait speed, physical activity, and fatigue, making walking an appropriate therapeutic target for decreasing frailty. Further, aerobic capacity is decreased in frailty beyond normal age-related changes, making ADL completion difficult as these tasks require an individual to operate at near maximum capacity. A VO2 max of 18 mL/kg/min or greater is required to complete most ADL tasks, yet research estimates frail older adults have VO2 values under 16 mL/kg/min.10 Interventions that improve physical capability and physical activity are likely to improve the ability to complete ADLs to help older adults maintain independence and avoid nursing home placement.

In the LIFE-P study, individuals received 150 minutes of weekly walking at a Borg Rating of Perceived Exertion of 12 to 14 (somewhat hard), ie, moderate intensity.11 This walking intervention was associated with a 0.43 out of 5 decrease in the number of frailty criteria present at six months, with the greatest impact on sedentary behavior time. Importantly, when sedentary behavior was omitted from the frailty phenotype, the low-moderate intensity intervention did not impact frailty, demonstrating that low-moderate intensity walking had equivocal effects on the frailty syndrome while predominantly influencing sedentary behavior time. In comparison, high intensity intervention has shown promise in reducing frailty. Data from animal models, adults with neurologic impairment, older adults with COPD, and healthy older adults indicate that the degree of walking intensity is a critical variable influencing outcomes.12-14

In a small pilot study of high-intensity walking for prefrail and frail older adult assisted living residents, 12 sessions of walking for 30 minutes at a 15 to 17 (hard to very hard) on the Borg Rating of Perceived Exertion Scale was associated with substantial reductions in frailty on the SHARE-FI, increased gait speed, improved six-minute walk test (a measure of cardiovascular endurance), and significant differences in balance on the Berg Balance Scale.15 Importantly, average daily step counts also increased 17% after the five week intervention, suggesting that improved capability contributed to less sedentary time.

It is critical that exercise is dosed at a proper intensity to improve muscle strength and mass gains. Unfortunately, underdosed resistance exercise is common and has been identified as one of the treatments that should be avoided in the Choosing Wisely campaign (choosingwisely.org). Older adults are often prescribed low-intensity exercises that are inadequate to develop muscle strength, and the irony is that this occurs more often and with greater underdosing in those with frailty who would benefit the most from appropriately dosed exercise. The current recommendations for older adults with frailty are moderate-to-high intensity resistance training (5-6 on a 0 to 10 scale) and aerobic exercise at 70% to 80% of maximum heart rate.7

Conclusion
The evidence is clear. All older adults, but particularly those with frailty, need to be more active. The Exercise is Medicine initiative encourages all health care providers to assess physical activity and prescribe exercise or refer patients to a physical therapist or a certified exercise professional. As with any medication, the effectiveness of treatment is subject to proper dosing and adherence. Providers can ensure proper dosing of the exercise medication by focusing on intensity. Helping older adults exercise at a therapeutic intensity will help them optimize outcomes in response to intervention to ensure their highest level of function.

— Margaret Danilovich, PhD, PT, DPT, GCS, is a physical therapist and assistant professor at Northwestern University. Her clinical focus is the care of older adult patients in long term care. She conducts research on the role of exercise interventions in reducing frailty and improving mobility among older adults.

References
1. Robinson TN, Walston JD, Brummel NE, et al. Frailty for surgeons: review of a National Institute on Aging conference on frailty for specialists. J Am Coll Surg. 2015;221(6):1083-1092.

2. Fried LP, Tangen CM, Walston J, et al. Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001;56(3):M146-M156.

3. de Vries NM, Staal JB, van Ravensberg CD, Hobbelen JS, Olde Rikkert MG, Nijhuis-van der Sanden MW. Outcome instruments to measure frailty: a systematic review. Ageing Res Rev. 2011;10(1):104-114.

4. Mitnitski AB, Mogilner AJ, Rockwood K. Accumulation of deficits as a proxy measure of aging. ScientificWorldJournal. 2001;1:323-336.

5. Romero-Ortuno R, O'Shea D, Kenny RA. The SHARE frailty instrument for primary care predicts incident disability in a European population-based sample. Qual Prim Care. 2011;19(5):301-309.

6. Morley JE, Malmstrom TK, Miller DK. A simple frailty questionnaire (FRAIL) predicts outcomes in middle aged African Americans. J Nutr Health Aging. 2012;16(7):601-608.

7. Aguirre LE, Villareal DT. Physical exercise as therapy for frailty. Nestle Nutr Inst Workshop Ser. 2015;83:83-92.

8. Target heart rate and estimated maximum heart rate. Centers for Disease Control and Prevention website. https://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm. Updated August 10, 2015.

9. Burton E, Lewin G, Boldy D. Physical activity preferences of older home care clients. Int J Older People Nurs. 2015;10(3):170-178.

10. Liu JY. The severity and associated factors of participation restriction among community-dwelling frail older people: an application of the International Classification of Functioning, Disability and Health (WHO-ICF). BMC Geriatr. 2017;17(1):43.

11. Cesari M, Vellas B, Hsu FC, et al. A physical activity intervention to treat the frailty syndrome in older persons — results from the LIFE-P study. J Gerontol A Biol Sci Med Sci. 2015;70(2):216-222.

12. Seldeen KL, Lasky G, Leiker MM, Pang M, Personius KE, Troen BR. High intensity interval training improves physical performance and frailty in aged mice. J Gerontol A Biol Sci Med Sci. 2018;73(4):429-437.

13. Schenkman M, Moore CG, Kohrt WM, et al. Effect of high-intensity treadmill exercise on motor symptoms in patients with de novo Parkinson disease: a phase 2 randomized clinical trial. JAMA Neurol. 2018;75(2):219-226.

14. Guadalupe-Grau A, Aznar-Laín S, Mañas A, et al. Short- and long-term effects of concurrent strength and HIIT training in octogenarians with COPD. J Aging Phys Act. 2017;25(1):105-115.

15. Danilovich MK, Conroy DE, Hornby TG. Feasibility and impact of high intensity walking training in frail older adults. J Aging Phys Act. 2017;25(4):533-538.